"Protestant"
oh that's easy.
An Ant that's on Protest....
ok seriously it is a term used for the split from the Roman Catholic church, kicked off by Martin Luther nailing a document to the church doors that protested about the way the Church was run and how he believed they had strayed from the faith by doing things like selling induglences and praying to the saints (especially the Virgin Mary) instead of directly to God.
Most of the churches we have except for the Eastern Orthodox and Roman Catholic church are considered Protestant though not all are "Reformed" lol that's another one people throw around and I've found needs defining to makes sure everyone is on the same page.